Valve-gear.



J. A. SEYMOUR.

VALVE GEAR. APPLICATION FILED MAY 28, 1913.

witwwm wuwwtoz YMOU/T KL *IlE AORRIS PETERS co, Du nml ITHO, WASHINGTON D. L.

J. A. SEYMOUR. VALVE GEAR. APPLICATION FILED MAY 28, 1913.

1, 1 11,327, Patented Sept. 22, 1914.

3 SHEETS-SHEET 2.

3 wue/wboz Ja /woof? THE NORRIS PETERS 60., PHOTO-LITHQ, WASHINGTON D. C.

J. A. SEYMOUR.

VALVE GEAR.

APPLICATION FILED MAY 28, 1913.

v Patented Sept. 22, 1914.

3 SHEETS-SHEET 3.

' 8mm Czliaewnaul? GS 2115 v wi mmeaz W THE NORRIS PETERS 60.. PHOTO-LITHO. WA /Nsmfv. D. c

- "steam'engines oifwthegeneral class described To all whom it may concern:

- Be" it known that LlJaMns Anwann SEY- have invented certain new and l lowing'is a fullpclear, and exact description.

t and made irregular.

i so

valve 1 is This invention relates to improvements in the operating mechanism of flat gridiron valves-such'as applied to'the cylinders of in my prior Patent No; $328,121, dated July 4, 1899, and consists in certain novel arrangements and combinations-30f the valve actuating mechanisms whereby the 'movement imparted to the-valves without theuse 4 motion of the eccentric, or '1 other actuating dev'ce,by means of connectof cams by the 7 ing devices interposed betweennsaidactuatsaid valves, isadistorted I I One "of-the main .dif-

ing device and the ferences between the presenti'nvention and that shown in sa d patentis that in; said and" port, andl'one main'steam valve and port, both of these valves being driven by a fixed eccentric, and superimposed upon the main'steam valve, an auxiliaryIcut-ofivalve drivenby an eccentric "under? control of a governor;

at each end of the cylinder,

especiallyimportant with valves of the 'grid- "iron typegtojreduce the unnecessary valve motion when closedrns ab y vew f ferr dto in are an execs in width of valve 'Z Ilri f e h g i e trend n B n i f-VALVE-GEARL" In the present invention the; cylinder has four valvesflwith one exhaust valveand'port and one st eamvalve and port 'I and the exhaust 1 valves gare driven b mechanism entirely from that driving the steamtvalves, I

avhich latter arepdriven by the governor-i ec centric ashereinafter described, One objct'bf the distortion and irregularity flof the speed of moveinent ofithe valv es re fefrred 't'o isto givetlie valves such travel asshall-be necessaryfto secure "adequateport; opening and a s'ufiicient;seal'whenclosed, and to sup pressfurtlieifiunnecessary valve motion such 7 asusually -takes; placeafterthe closing of v Q theva lve,'by :hav'

[fine the motion I fthe valve at one end of H the strokej A tfthis time an unbalanced uncle conslderablesteam pressure, 3 producing proportionate friction, and t" is:

materially greater than'ltliat necessary to aiiordnzt proper tsealjat both edges of the port when closed. It; is evident that if there is an excessive movement of the i-valve when closed, the widthfiof'thevalve gridmust be e i e 22 a.

correspondingly increasedl as comp ared with the width; of' the portin order to prevent opening upfof thepojrt on the side opposite that at 'whichjclosin'g takes place. 4 Underordinary conditions, if the 'reg-ular motion of the eccentric were impar'ted'to agridiron steamwalve of sufiicient magnitude to secure proper port opening,j:the motion, while the valve was closedywouldbeso great and the corresponding width offvailve' grid would be so greatly 'increa'sedf-that the 'size of the valve and valve seat would be increased to" what wouldbe aprohibitive amount, having in vieweconomical-proportions of the en-; gine from a constructive standpoint, and also the keeping of the total volume of the 5 port from valve tocylinder'down to areasonable amountg This' p ortvolume constipaten't'a six valve cylinder is used havingat f each end of thecylinderone exhaustwalve 1 tutes a part of'th'e waste, or so-called clearance space .of -thje cylinder, whichit is de+ sirable to keep as small as possible to.secure economyinsteam consumption; a A pause, or dwell, in the motionof the valve asabove described is accomplished by puttingin the' valve mechanism whatis commonly known as wrist' plate effectyconsisting of a driving rocker-having a reciprocating or rocking movement, connected with suitable pins by a link toj a driven rocker or slide also having "a reciprocatingmovement, the motiOnEof the pin in :the driving rocker to which the said connecting link istattached being inclined or. 'unsymmetrical with' reference to: the position-of the pin in driven rocker or slidei to which the connecting link is also attached.

'- A single wr'ist plate'motion interposed in a sufiicient dwell 01" pause motion for a gridironjexha'ust valve, which should be'open about one-half off-a revolution, and the com:- bination jot-such" a wrist platefmec'hanisni with such an exhaust valve is" not novel.

WVith a gridiron steam fvalve "controlling both thejadmissionand the ,cut-ofii of the the valve driving mechanism will give a steam, the case is different in that onevvrist a plate effect will not give sufficient dwell,

the periodofopening of the steam valve for the latest c'ut off; being usually "less than three eighthlsfi of at revolution,'} 'and "under ton. Otherwise cylinder at most ends-of the cylinder.

method forsecur-ingequal cut-offs at both ends of the cylinder is objectionable and more or less inefi'ectivefwith positivelyj 1 driven valves, especiallyv when of the gridiron-type described herein. 1 a a In the accompanying drawings, Figure 1 is ;an elevation showing :a partial sec-' j-tion .ofthe frame end 2-is an elevation showing the .frame "end steam valve driving mechanism, :a shaft associated parts. Fig. 3, is a top plan view of the'en gine conventionally shown. Fig. 4- is .an 5 end elevatiompartly in section, of the valves usual working conditions much less than this proportion. This means that amuch greater proportional "amount 'ofthe regular" eccentric motion must be suppressed than "is necessary for the exhaust valve, in order to avoid unnecessary valx e vmotion when closed and consequent excessivefwidth of port grid, and it requires the placing- 0f two-or more- Wrist plate 'efiects in series, between the steam valve audits-actuating device, which is an eccentric under the :controlofa shaft governor. ,This governor regulates the ten-act :the "effect of the angularity of the connecting .rod-upon the motionof the pis- 1 v a difierence will; exist bej tween, the cut-cits at the two ends of-the This-defect cannot be corrected for all-loads by making the loads.

steam" valve admissions dissimilar at the two valve igear. Fig.

governor, "and certain and valve gear at one endof the-cylinder.

Thegovernor', as" shown, consists of 13/1681!- trifnga-l weight .W, pivoted to anarm V" of the iiywheelfl by-a pinpfisaid weight haviforcelwopposed by the spiral spring T attached to an arm of the pin-p Theweight W is ing its centrifugal a link :A throughpin p ing upon the fixed eccentric boss I, which is keyed fixedly to the shaft K. :lVhen the- ;centrifugal weight W moves. from its in ner apositiomfin which it'is shown, to its: outermost;position, thecenterof pin 72 will move-fromtheangleaf toward angle.e. At

' l the same timet-he pin will move from the iangle laitoward (the angle e? (by reason of the connectinglinl: A causingsthe governor eccentric J to turn upon the fixed eccentric tric J upon the ball'pin-B This last mentioned m oti on from boss I so that the center of the governor eccentric will move from the angle 9 repres'enting the mum and minimumcut-o respectively.

The eccentricstrap L drives with universal connections at both endsifro'm the eccenangle g"towa rd osltlons of max on the rocker G situated upon *t'hesteam valve lay shaft 0.

It will be noted that the representing. the. lower and upper positions of I the center of the .ball pin .13 respectively, correspond to -:the angle points-g and wk. of the centerao fthe governor eccentric,- and that the i'rline I of motion ax-is of nth-e shaft does noti pass :through' the center iof the shaft. "Therefore, the mot on of s the 'eccent-ric as "received zbythe p111 Bus distorted inasmuch asatheextrerne positions of the center "of spin B, :6. points, ,9 and i correspond to 'the positions .of the center of of :the center *9 0f 1 this pin in a plane atright angles :to the points 9, and h,

the eccentric gand .hgwhich latter are not opposite to -each other. Furthermore, :there is :a further distortion due to {the angularity r of the v=eccentri'c strap ,connection L from the eccentric-J totheYpinB The proportions of the respective qposis tion's and strokes are so made that the desire'dvcorrection is obtained in the motion of'the lay shafit-orrock shaft 0 to counteract: the 'effect' upon the position of the piston necting rod, "and of the angnlarityof; the icon equal cutoffs at both :ends of the cyllnder aresecuredat all loads. 1

Fig'. 3.=.=show-s in ageneral way the location' oftheflywheel V which contains the governor, ithe; governor eccentric sleeve J,

thexsteam valve e'ccentric strap L, and the exhaust :valveeccentricstrap F,"driv ing;re- ,spect'ivel'y the steam valv'e'gl'a'y shaEEtO and .thewexhaust valyelayshaft N which lead back, as showni to the cylinder valve gear situated by thefside ofthe cylinder-Cr,

valve driven from the.roek shaftzNltorsocalled exhaust waive lay shaft) throughgthe connecting QgGKIT HS-SIIOWIL The rock; shaft Ovisthesteam valve layshaift'. The rockeri 1' of theflink D through thepinsgpandpf the rocker G ,jcurnaled v onathe pivotM j It will be V-n'oted' -that the angle 1 ines ,a

and 0, representing the extremes o'f fniotion of the center of the pinangle linelb 'representing the .middle olnt' of such mo lay'shaft O "drives-by. means 3; 115

tion, correspond ,torthe po'si tions of the" 72 indicated by the position; of angle:lines a, 'C LI1Cl b, respectively, showing that, the

I) too, representedhy the anglellines bsand 0 has been m 'uch',lessensd in rockerG, while-the motion from'fi qz tollb,

extreme upper position fdenoted byangle lineal when the centerof the pin direct line'betvveenTthe', center of t is in'a I e shaft OJ; and pin "p,;;fthi's positionyof the pin i being denoted byjangl'e 1ine e.- ,The pointcff become theextreme of motion oftheceases to p 7 center ofthe pin p, although the corresponding angleline'c of the] center of the pinp is the point of extreme motion of thislatter pintv It is .evidentvthat'the center of the pin p v point 6' 1 instantaneous Velocity of the center ofpin the driving rocker, the

j to c,

H to pin 9 on I I irectly driven from this lever'U will-makealsma'll stroke from the point a; and back again to c while the center of the pin pie passing from point )6 to point'cand back again to point-e, also, that i the velocityof the pin p as compared with r15 the velocity ,of the "pin 2) becomes diminished as the center ofthe pin p approaches the "in either direction, and that the Itwill be noted thatthe rocker G, the

H, and the lever xUpfform the. driving rocker, the connecting link and the driven rocker of a secondwri'st plate in will be noted that angle 'lines 0?, b

i 0*. and 6 represent the same positions of the rocker arm G in angular motion as the an nn S a, 6, 0'1 and and that the a 'an-glelines (1?,16 andf c? (or afl band c, a

which represent the'same positions in angular motion of the lever "U) correspond to the, angle'lines a, 7) and c of the 1110- a, tion-of the rocker G, and hence to angle lines a, b, and 0 respectively" ofthe motion of the lay shaft O; means of the second Wristnplate efiect the pointb has been movedstill farther toward the point 6 v motionsubstantially suppressed.

andjone-half. of the original It Will be understood-what I have defscribedin detail only "one'isteam, valve With ,:its corresponding branch train of rist plate motions, the same being :shovvnin Fig. t, andthatthe other steam valve is provided I i Copies ,0! this patent may be clitained t or five cents each, by addressing the Commissioner of Iatents,

1 wash'm t nc,"

branch V p a; driven -;In other, Words, by

Wrist plate with a similar branch train from the train of mechanism connecting. the governed eccentric. What I claim is: v,

1. In a steam engine, the combination of .a of gridiron valves for. controlling th admission and, cutting off of the steam, a shaft governor'controllingthe speed of the engine by varying the position of the ec- CGIIJEIIC usedto actuate said ypair of valves, a connectingv train of mechanism for conveying the motion of said eccentric with branches to each valve, and ineachbranch a pair of Wristplate motions in series; each Wrist plate motion consisting of, ardriving rocker, a connecting link, and a .driven rocker turning upon a 1 fixed stationary shaft or pivot; the; driven rocker of the wrist plate motion which is nearer the eccentric 1 and the driving rocker of the Wrist plate motion Which is nearer the valve being rigidly connected together and pivoted upon said fixed shaft.

2. In a steam engine, the combination of a pair of gridiron valves for controlling the admission and cutting off of the steam, a shaft governor controlling the speed of the engine by varying the position of the cocentric used to ac-tuate said pair of valves, a connecting tram of mechanism for conveying the motion of said eccentric including a rocker pin deriving motion from said eccentric, which motion is in a path which,

if extended, will passat somedistance from I the center of the main shaft "upon vvhich the eccentric is situated, said pin being so placed as to distort itsmotion as received from the eccentric substantially as described; and said connecting train also including branches to each valve and in each a pair of wrist plate motions in series; eachiwrist plate motion consisting of a driving; rocker, a connecting link and rocker turning-upon a tionary'shaft or pivot; the driven rocker ofthe' wrist plate motion which is nearer the eccentric and the drivingrocker of the motion which is nearer the valve being rigidly connected together and pivoted upon said fixed shaft;

JAMES ALWARD SEYMOUR. Witnesses: i E. E: MORSE,

IDA M. HUNZIKER. 

